The fiercely original film-maker, poet and artist Jeff Keen, who has died aged 88, defied categorisation. He produced a vast body of paintings, drawings, sculpture and punchy Beat poetry, but is best known for his films, which incorporated collage, animation, found footage and live action – often all in one work. Keen used highly innovative techniques of superimposition and editing, and frequently etched and degraded the film surface. Works such as Marvo Movie (1967), Rayday Film (1968-75) and Mad Love (1972-78) were shot with his friends and family either at home, on the streets of Brighton or at the local tip; their fantastical, DIY countercultural qualities evoked the spirit of Andy Warhol's Factory and the early cinema pioneers of Brighton, where Keen lived. Despite making his first film in his late 30s, he completed more than 70 films and videos throughout his life.

Keen was born in Trowbridge, Wiltshire, and had a love of wildlife, art and books as a child. He attended grammar school and gained an Oxford scholarship, but this was thwarted by his national service in 1942. Keen was given experimental tanks and aeroplane engines to trial during the war, and would frequently refer back to this period in films such as Meatdaze (1968), which included bombers and sirens on its soundtrack, and Artwar (1993).

When able, Keen made drawings virtually every day for the last 20 years of his life. Photograph: Matt Hass

After the war, Keen developed a love of movies and comics and attended a small art college in Chelsea. London life encouraged his love of the arts, especially surrealism, Picasso and Dubuffet. When he moved to Brighton, Keen took up work as a landscape gardener for the local council. In 1956, he married Jackie Foulds, who was the muse for his films in the 1960s and 70s, playing the characters Vulvana, The Catwoman and Nadine. Keen himself had a B-movie-style "mad scientist" alter ego named Dr Gaz.

One of his early films, The Autumn Feast (1961), was made with the poet Piero Heliczer, who was part of the Warhol set. From the early 1960s, Keen experimented with "expanded cinema" (film events that exceed the normal modes of cinema projection), combining multiple projections and live art performance. A regular contributor to the "happenings" scene of 1960s London, at the Better Books shop in Charing Cross Road and elsewhere, he also participated in the International Underground Film festival at the National Film Theatre in 1970 and continued to make expansive, surrealist-informed 16mm epics such as White Dust (1970-72) and The Cartoon Theatre of Dr Gaz (1976-79), as well as 8mm diary films. He painted throughout the 60s and 70s and made artist books inspired by his films.

Keen's films, such as Marvo Movie, were made with his friends and family, and evoked the spirit of Andy Warhol's Factory.

After Keen temporarily separated from Jackie in the early 1980s, his films became more abstract and introspective. He worked in front of the camera more, sometimes donning absurdist paper disguises, almost as if life had not only merged with art but fully collapsed into it. In Blatzom (1986), he became a moving sculpture/drawing hybrid. His friends and family were still involved: his daughter, Stella, operated a second camera and the editor Damian Toal came on board to help with violent, industrial-style videos such as Plasticator (1990s). Artwar was commissioned and broadcast by Channel 4.

Keen's interest in myth, surrealism and romantic painting complemented his love of movies and comics, and he continually absorbed new references into his work. His highly frenetic videos of the 1990s included homages to Apocalypse Now, Rambo and Predator as well as Budd Boetticher westerns. Although his work has always been featured in historical surveys of British experimental and avant-garde cinema, these qualities distinguished his films from more purely formalist works made at the London Filmmakers' Co-Operative, an organisation he helped to found in 1966. It meant his work was often more appreciated by skaters and punks than followers of the canonical avant garde. The extreme, short edits in his playful, visceral films have helped to keep his work fresh and alive; they still zap with energy decades later.

When able, Keen made drawings virtually every day for the last 20 years of his life. His art, which ranges from beautifully worked paintings to surrealist assemblages, collages and free-form drawings, has been rarely shown, but recent exhibitions in Paris and New York initiated by Stella have resulted in new critical acclaim. A Keen installation and related events will be presented at Tate Modern's new Tanks exhibition space in September 2012.

I worked with Keen throughout 2008 on a series of restorations, a film season and a BFI DVD boxset, GAZWRX: The Films of Jeff Keen. The process was undertaken at great speed, much like the pace of his films. We discussed everything from B-movies to Wagner to William Blake. I followed his instructions diligently along the way, but discovered that in speeding up some electronic drawings made on a children's toy, and turning them into a two-channel video, we had made a new piece of work, Omozap Terribelis + Afterblatz 2. He grew excited and wanted to make more new things, despite his declining health. It was typical of what had been his persistent desire, even need, to make art. As he said in the early 1960s: "If words fail, use your teeth. If teeth fail, draw in the sand." Whatever it takes, art must happen.

Keen is survived by Jackie, Stella and his sisters, Rosemary and Cecilia.

• Jeffrey John Spencer Keen, film-maker, artist and poet, born 26 November 1923; died 21 June 2012